1. Field of the Invention
The present invention relates to a lamp socket structure, and more particularly to a lamp holder and socket structure for miniature decorative light, to which a miniature decorative lamp or a miniature light-emitting element can be securely and safely mounted and then connected to conductors.
2. Description of the Prior Art
Decorative light strings are widely used in festivities, particularly in Christmas. Such light string typically includes a power cord to which a plurality of lamp sockets are connected for holding decorative lamps thereto. Recently, miniature light-emitting elements or miniature decorative lamps are used to produce light strings that provide attractive visual effect through densely distributed fine decorative lamps. Thus, these miniature decorative lamps and light-emitting elements have been largely employed in Christmas light strings and tend to replace the position of conventional normal-size decorative lamps.
Such decorative light strings can be used indoors without taking too much consideration about the electrical safety and structural strength thereof. However, to use these decorative light strings outdoors, it is a must to consider particularly the electrical safety in use thereof. For example, the light strings must be provided on power cords that have enough thickness to provide the light strings with sufficient tensile strength. However, this condition inevitably complicates the relation among the power cords, the lamp sockets and the lamps, and makes the light strings more difficult to handle.
With conventional skills, the miniature decorative lamp is associated with the lamp socket and connected to the power cord generally by directly soldering copper conductors of two wires to two connecting wires of the miniature decorative lamp, and then putting a thermal-shrinkage sleeve around each joint of the lamp and the socket, which is then heated with a heat source, such as a hair dryer, to thermally shrink the sleeve, so that the shrunk sleeve tightly encloses the lamp and the wire as well as the soldered joint of them to serve as an insulating material thereof. The above-described conventional skill for producing light strings is completely manual and has low productivity. Moreover, the light strings so produced are subject to damage due to external pressure and are not safe for use.
It is therefore a primary object of the present invention to provide a lamp holder and socket structure for miniature decorative light that enables a miniature decorative lamp to securely mount on the lamp socket while the lamp socket allows wires having big thickness to connect thereto.
Another object of the present invention is to provide a lamp holder and socket structure for miniature decorative light that provides better electrical safety for use. After the miniature decorative lamps are associated with the lamp sockets to produce a light string, the light string can be used with high electrical safety.
To achieve the above objects, in accordance with the present invention, there is provided a lamp holder and socket structure including a lamp socket, a miniature lamp holder, a pair of metal contact plates, a pair of wires, and a miniature decorative lamp. The miniature lamp holder includes a body portion having a lower opening and an upward tapered extension portion above the body portion. The extension portion is provided at a top with an upper opening for the miniature decorative lamp to mount thereto. A middle dam is formed in an internal space of the body portion of the miniature lamp holder to separate the lower opening thereof into two through holes. A lower part of the middle dam projects from the bottom of the miniature lamp holder to provide a projected dam portion.